JPS61151818A - thin film magnetic head - Google Patents

Abstract

PURPOSE:To obtain a thin film magnetic head that can be easily produced with high accuracy by forming a groove at a part of a magnetic substrate, putting a coil conductor into the groove for formation of a flat surface and forming a gap at the upper part of the coil conductor of an upper magnetic core set as if it covered the coil conductor. CONSTITUTION:A copper substance serving as a coil conductor is put into a groove 5a of a magnetic substrate 5 serving as a lower magnetic core. Then a lapping process is applied so as to obtain the substrate 5 having a flat surface including buried coil conductors 6 and 6'. A soft magnetic film is formed and then undergoes an ion etching process for formation of a magnetic core half 7a of upper magnetic cores 7 and 7'. Then this half 7a is shaped by a diamond cutting tool for formation of a gap surface 9. Then an SiO2 film 10 is formed by a sputtering process in the form of a head gap. A soft magnetic thin film is formed on the film 10. Then the soft magnetic thin film provided on the half 7a is removed by a lapping process. Thus a magnetic core half 7b is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a thin film magnetic head used in magnetic tape storage devices and the like.

[Background of the invention]

Various types of thin-film magnetic heads have been proposed in the past, but one example of this type is disclosed in Japanese Patent Application Laid-Open No. 59-3022.
As shown in Publication No. 0, a coil conductor and an upper magnetic core covering a part of the coil conductor are formed on a magnetic substrate serving as a lower magnetic core by a thin film formation technique,
It is known that a magnetic gap is formed at the end of the joint surface between the upper magnetic core and the magnetic substrate.

FIG. 3 is a perspective view schematically showing this type of thin-film magnetic head, in which 1 is a magnetic substrate serving as a lower magnetic core;
3 is a coil conductor provided on the magnetic substrate 1; 3 is an upper magnetic core provided on the magnetic substrate 1 so as to cross -S of the coil conductor 2; 4 is a coil conductor provided on the magnetic substrate 1 and the upper magnetic core. A magnetic gap formed at the end of the joint surface with 3,
The magnetic tape slides on the magnetic gap 4.Due to its structure, this type of thin film magnetic head has a track width or gap length that is determined by a well-known thin film forming technique (photolithography, vacuum evaporation, sputtering, etc.). Although it can be machined with high precision, the dimension from the coil conductor 4 to the tip of the magnetic gap 4 is large, and there is a drawback in terms of magnetic efficiency. Therefore, as a means to compensate for this, mechanical methods such as ultra-precision grinding are used to process the gap. It is conceivable to reduce the depth as much as possible, but in this case, the wear life of the magnetic head is shortened and the applicable system is limited to systems with relatively little wear.

On the other hand, as shown in the perspective view of FIG. 4, the structure of the magnetic cores 1 and 5 and the coil conductor 2 of the other type disclosed in Japanese Patent Application Laid-Open No. 55-132519 is the same as that described above. The magnetic gap 4 is formed by magnetically cutting the upper magnetic core 5 in the width direction, which is different from the above-mentioned type.
The gap depth is determined by the thickness of the upper magnetic core 5. Therefore, in this type of magnetic head, the so-called gap-in-run type magnetic head, not only the track width and gap length but also the gap depth can be processed by thin film forming technology. In the second type of magnetic head, an upper magnetic core 3 is further formed on the magnetic substrate 1 and the coil conductor 2 provided in a stepped manner on the magnetic substrate 1 by thin film formation technology. However, it is difficult to control the film thickness of the upper core 5 at such a stepped portion, and it is also difficult to finish the magnetic gap 4 with high precision. The object of the present invention is to provide a thin film magnetic head that has a long wear life, can be highly accurate, and is easy to manufacture.

[Summary of the invention]

To achieve this objective, the present invention forms a groove in a part of a magnetic substrate that becomes the lower magnetic core, buries a coil conductor in the groove to flatten them, and crosses the coil conductor. The present invention is characterized in that a single upper magnetic core is magnetically cut in the width direction to form a magnetic gap above the coil conductor of the upper magnetic core provided to cover the magnetic core.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view schematically showing an embodiment of a thin film magnetic head according to the present invention, in which 5 is a magnetic substrate having a lower magnetic core, 5& is a groove, 6.6' is a coil conductor, 7.7' is an upper magnetic core, and 8.8' is a magnetic gap. The magnetic substrate 5 is made of soft magnetic ferrite, and the grooves 5a formed in a predetermined pattern in the magnetic substrate 5 have grooves 5a. A coil conductor 6.6' made of steel is embedded above the magnetic substrate 5 and the coil conductor 6.6'. il is flattened ◎The coil conductor 6.6 is placed on the upper magnetic core 7゜7'.
The magnetic gap 8.8' is provided on the magnetic substrate 5 and the coil conductor 6.6' which are flattened across the upper magnetic core 7.7' located on the coil conductor 6.6'.
It is an inline array.

FIG. 4 is a sectional view showing the main manufacturing steps of the above embodiment.

First, as shown in FIG. 4(A), a steel piece that will become a coil conductor is buried in the groove 5 of a magnetic substrate 5 (soft magnetic ferrite) that will become the lower magnetic core, and then wrapped to a thickness of 5 μm.
Then, a flat magnetic substrate 5 is obtained by embedding the coil conductors 6 and 6'. Next 1 These magnetic substrates 5 and coil conductors 6
．． A soft magnetic thin film is formed on top of the upper magnetic core 7.7' and formed into a desired pattern by ion etching.
After forming the magnetic core half 7a, the rough side surfaces of the magnetic core half 7a produced during the ion etching are shaved with a diamond cutting tool to form the gap surface 9.
0 At this time, the tip of the cutting tool is connected to the coil conductor 6.6
By shaving so as to reach a part of the upper surface of the magnetic gap 8.8', the linearity of the magnetic gap 8.8' that is subsequently formed is obtained.

Next, as shown in Fig. 4 CB) K, as a gap machine, S
In, 10 is formed by a sputtering method with a thickness of 3 μm, and a soft magnetic thin film is further formed thereon, and then the soft magnetic thin film deposited on the magnetic core half-hole 7a is removed by two-plying. As shown in Figure (C), the other magnetic core half 7bf of the upper magnetic core 7.7':
Form. Therefore, the above-mentioned S10. Although the film 10 is interposed as a magnetic insulating layer, its thickness determines the gap length, and in turn, the width and thickness of the upper magnetic core 7,7' determines the track width and gap depth.

In the above embodiment, a soft magnetic ferrite substrate is used as the lower magnetic core, but a soft magnetic thin film may be used instead.

Above, one embodiment of the present invention has been described for the case of a two-track multi-track magnetic head, and next, the present invention is not limited to such an embodiment, and the present invention is similarly applicable even if the number of tracks is different. Needless to say, it is a thing.

〔Effect of the invention〕

As explained above, according to the present invention, the track width, gap length, and gap depth can all be processed by thin film technology, and the film thickness of the upper magnetic core can be uniformly controlled. It is possible to achieve a high a degree of gap depth, which was previously difficult, and therefore has a long wear life.
It is possible to provide a thin film magnetic head that can achieve high precision and is easy to manufacture.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 (A)
, (n)s (c) is a cross-sectional view for explaining the manufacturing process of the embodiment shown in FIG. 1, and FIGS. 3 and 4 are perspective views of conventional thin-film magnetic heads.・5... Magnetic body substrate, 5a
...Groove, 6.6'... Coil conductor, 7.7'...
・Upper core, 8.8'...magnetic gap 0 7° self-explanation as shown in the drawing! : Yasute Toshi) 1st Ge 22 ■ Figure 3 Full procedural amendment (method) Indication of the case 1982 Patent Application No. 272969 Name of the invention Person who corrects thin film magnetic head Patent applicant's name 15101 Tot Co., Ltd. Manufactured by Hitachi
Subject of amendment by the drafting agent: Brief description of the drawings in the specification and all drawings (Figures 1 to 4). Contents of amendment 1: "2" on page 8, line 6 of the specification was corrected by "4"K.

Claims (1)

[Claims] A magnetic substrate serving as a lower magnetic core, a coil conductor provided on the substrate, an upper magnetic core provided across and covering the coil conductor, and magnetically cutting the upper magnetic core in the width direction. In a thin film magnetic head having a magnetic gap formed by forming a groove, a groove is formed in a part of the substrate, the coil conductor is buried in the groove, and the upper surfaces of the substrate and the coil conductor are flattened. A thin film magnetic head characterized in that the magnetic gap is arranged above a conductor.